Dogs are known for their olfactory superpowers, leading to jobs as drug sniffers and as helpers in search and rescue efforts. Now, those sensitive noses are being credited with something closer to home: being able to detect when their owners are stressed. New research published Wednesday in PLOS One notes that scientists from Queen's University Belfast collected breath and sweat samples from three dozen human volunteers, both before and after they completed a mind-bending math exercise of counting backwards from 9,000 in units of 17, without the use of pen and paper, reports NBC News.
Then, using four dogs trained to point their noses at samples from a stressed person, the researchers offered the canines three choices: a piece of unused gauze, a piece of gauze wiped with a sample from an unstressed person (ie, someone who hadn't yet completed the math task), and a piece of gauze wiped with a sample from a stressed person (someone who had). The scientists found that the dogs accurately picked out the "stressed" samples with an accuracy that ranged from 90% to nearly 97%. Previous research has found that the compounds found in human breath and sweat undergo a chemical change when a person is under acute stress, which can alter the scent of the air and bodily fluids emitted from humans.
The BBC notes that canines' sense of smell has already been used not only to track down drugs, explosives, and missing humans, but also to detect physical conditions such as diabetes, different types of cancer, and even COVID. Now, thanks to this new research, they may get credit for unearthing psychological conditions as well. Although the sample size used was small, researchers hope their work will one day lead to advances in the training of therapy dogs. "This study provides further evidence of the extraordinary capabilities of 'man's best friend,'" study lead author Clara Wilson tells NBC. Here, some more tasks dogs can perform with those nozzles. (Read more discoveries stories.)